JP2008147112A - Planar heating element, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar heating element capable of preventing temperature drop of a joining part because there is a problem where temperature is dropped because a PTC resistive element is not arranged in a part of each joint line when a plurality of planar heating elements are arranged. <P>SOLUTION: By folding a part (an end of this planar heating element 1) excluding a PTC resistive element 3, the PTC resistive element 3 can be arranged in the whole of an installation area. Thereby, temperature drop of a joining part of the planar heating element 1 is prevented, and installation efficiency of a heating part with respect to the installation area can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a planar heating element characterized by positive resistance temperature characteristics and a manufacturing method thereof, and more particularly to a heating element having improved installation efficiency and a manufacturing method thereof.

  Conventionally, a PTC resistor using a conductive polymer having a positive resistance temperature characteristic has been used. Here, the positive resistance temperature characteristic means that the resistance value of a substance increases as the temperature rises, and increases rapidly when reaching a certain temperature. A conductive polymer that is formed by mixing a crystalline polymer and a conductive material is widely known. The principle is that, due to the rapid volume expansion when the crystalline polymer is converted from crystalline to amorphous, the average inter-particle distance of the conductive material dispersed therein increases, resulting in resistance. The value also increases. Since the PTC resistor based on such a principle retains its own temperature control function, there is an advantage that the number of components can be reduced without providing a safety device such as a thermostat (for example, Patent Document 1).

FIG. 4 is a configuration diagram of a conventional planar heating element, in which a PTC resistor 17 is printed on an electrode 16 disposed on a resin film 15 and dried. In addition, a protective film may be laminated thereon. In this configuration, the portion that generates heat as the heater is only the planar shape of the PTC resistor.
JP 2001-357966 A

  However, in order to print and shape the PTC resistor on the resin film of the base material, a clearance is ensured in terms of the construction method, and a portion that is not printed (part 18 excluding the PTC resistor) is generated. Further, when the planar heating element is completed, a part 18 other than the PTC resistor may be cut off. However, if the distance from the electrode 16 or the PTC resistor 17 to the end face of the planar heating element is short, impurities such as moisture Since the quality mixes into the electrode 16 and the PTC resistor 17 and causes a decrease in reliability, it cannot be cut off. That is, when the conventional configuration is used as it is, a portion that is not a PTC resistor occupies a certain area, and thus a portion that does not generate heat is generated.

  The present invention solves the above-mentioned conventional problems, and is a planar heating element in which the installation efficiency of the heating part is improved by bending a part excluding the PTC resistor to 90 ° or more with respect to the PTC resistor. The purpose is to provide.

  In order to solve the conventional problem, at least a part excluding the PTC resistor is bent and arranged at 90 ° or more with respect to the PTC resistor. Since the PTC resistor can be disposed on the entire installation surface by bending, the installation area (installation efficiency) of the heat generating portion with respect to the installation area of the planar heating element can be improved.

  Since the planar heating element of the present invention can reduce the installation area of the non-heating unit, the installation efficiency of the heating unit can be improved.

  A first invention is a first resin film having electrical insulation, a pair of electrodes and a PTC resistor formed by printing on the first resin film, and surfaces of the pair of electrodes and the PTC resistor And a second resin film having electrical insulation that covers the PTC resistor, and at least a portion excluding the PTC resistor is bent at 90 ° or more with respect to the PTC resistor. Thereby, since the area of the non-heat-generating part with respect to an installation area can be made small, the installation efficiency of a heating part can be improved.

  In particular, the second invention is configured to embed a part of the heat insulating material except for the PTC resistor of the first invention. Thereby, it can be set as the wedge for fixing a bending part to the support body of a planar heating element, and since a support body is a heat insulating material, thermal efficiency can also be improved.

  In particular, the third invention is configured such that a part except the PTC resistor of the first invention is wound around a heat insulating material. Thereby, the planar heating element can be further fixed to the support by the bent portion, and since the support is a heat insulating material, the thermal efficiency can be improved.

  In the fourth invention, in particular, the first resin film of the first invention is a polyester resin film. Polyethylene terephthalate, which is a polyester resin, has strength as a film and is inexpensive. Further, since the glass transition temperature is about 70 ° C. and the softening temperature is about 160 ° C., it can be easily deformed by heating at 200 ° C. or less, and can be bent at an acute angle of 90 ° or more.

  In the fifth invention, in particular, the second and third heat insulating materials have polyurethane as a component. The heat resistance of polyurethane is 80 ° C. to 90 ° C. and is cheaper than inorganic heat insulating materials. Therefore, it is useful when the planar heating element is used at 70 ° C. or lower. Further, when the polyurethane is cured, it can be adhered by bringing it into contact with a resin film.

  The sixth invention is a method of manufacturing by installing a heating regulation plate in the path of the laminated film in order to bend a part excluding the PTC resistor to 90 ° or more with respect to the PTC resistor. It is troublesome to cut out the laminated film and bend it accurately at room temperature. In the heating regulation plate of the present invention, it is possible to bend continuously and accurately without trouble by installing the heating regulation plate in the forming path of the laminated film.

  7th invention sets the temperature of a heating regulation board to 190 degrees C or less. When the resin film is a polyester film, the softening temperature is about 160 ° C. Therefore, by raising the temperature to about 190 ° C., which is higher than the softening temperature, the resin film can be bent with high accuracy without difficulty. When the temperature is higher than 190 ° C., the polymer material of the PTC resistor is destroyed and the resistance temperature characteristic is remarkably lowered.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic diagram showing the structure of a planar heating element according to a first embodiment of the present invention. FIG. 1 (a) is a perspective view, and FIG. 1 (b) is an XY of (a). It is a position sectional view.

In FIG. 1, a planar heating element 1 includes a first resin film 2 that is a base film, a PTC resistor 3 that is printed on the first resin film 2, and an electrode that is printed thereon. 4 and a second resin film 5 stacked thereon as a protective layer. Note that the PTC resistor 3 and the electrode 4 may be upside down.

  The first resin film 2 uses a commercially available 100 μm-thick low heat shrink type polyethylene terephthalate cut to a width of 300 mm. The PTC resistor 3 was prepared by combining several types of ethylene vinyl acetate copolymers, kneading and cross-linking carbon black, and using acrylonitrile butyl rubber as a binder to make an ink with a solvent. The electrode 4 is obtained by printing a silver paste in a comb shape and drying it. The number of combs is preferably thin enough not to break, and the thickness of the comb is determined by the resistance setting value. In the first embodiment, the PTC resistor is manufactured so that the heat generation temperature is about 45 ° C. As the second resin film 5, a commercially available polyethylene terephthalate having a thickness of 50 μm is cut into a width of 280 mm and used. The first and second resin films may be polyethylene naphthalate. There is an advantage that heat resistance is improved.

  Next, the laminating process will be described. The first resin film 2 and the second resin film 5 on which the PTC resistor 3 and the electrode 4 are printed are welded by a heat roller (not shown). The temperature of the heat roller was 170 ° C., and the welding speed (laminated film extrusion speed) was 90 cm / min. Then, in the process of extruding the laminated film, it is cut at regular intervals of 500 mm. Thereafter, the portion excluding the PTC resistor of the planar heating element 1 is bent to 90 ° or more. In this Embodiment 1, since it is 25 mm from an edge part to a PTC heat generating body, it bent at the part 20 mm from the edge part. The bent part may include a part of the PTC resistor as long as it includes a part excluding the PTC resistor. That is, in the case of the first embodiment, if the end portion is included, it does not prevent bending at a portion of 30 mm from the end portion.

  As shown in FIG. 2, a heat insulating material is joined to the planar heating element having the end bent in this way. FIG. 2A is a cross-sectional view of a configuration in which the bent portion 6 is inserted and fixed in the heat insulating material 7. FIG. 2B is a cross-sectional view of a configuration in which the bent portion 6 is wound around and fixed to the heat insulating material 7. In the former, the heat insulating material 7 is first laid on the installation part, and then the sheet heating element 1 is inserted and fixed in the cut of the heat insulating material 7, and in the latter, the sheet heating element and the heat insulating material are installed. It will be installed as a set.

  In the first embodiment, the heat insulating material 7 uses polyurethane. Although the sheet heating element can be joined after the polyurethane is cured by bringing it into contact with the sheet heating element before the polyurethane is cured, in the first embodiment, a cut is made in the pre-formed polyurethane and bent at that position. It was fixed by inserting the part.

  A plurality of planar heating elements arranged on the heat insulating material produced as described above were arranged and fixed in contact with the sides of the bent portions (not shown). Then, power is supplied in parallel by a power source (not shown), and the heat generation state is detected by an infrared thermograph (a device that detects infrared radiation energy emitted from the object, converts it to an apparent temperature, and displays the temperature distribution as an image). Observed. As a result, it was possible to suppress a decrease in temperature even at a connecting portion of a plurality of planar heating elements. In addition, the same effect was acquired even if what processed the part corresponded to said bending part around a heat insulating material.

(Embodiment 2)
FIG. 3 is a perspective view of a jig used in the method for manufacturing a planar heating element in the second embodiment of the present invention.

  The configuration and material of the planar heating element 1 are the same as those in the first embodiment.

  The laminating process of this embodiment will be described. The 1st resin film 2 and the 2nd resin film 5 with which the PTC resistor 3 and the electrode 4 were printed are welded with a heat roller (not shown). The temperature of the heat roller was 170 ° C., and the welding speed (laminated film extrusion speed) was 90 cm / min.

  And the laminated | multilayer film extruded passes the heating regulation board 9 installed in the post process of a heat roller, and an edge part is bend | folded continuously in the process. The heating regulation plate 9 has a flat entrance 10, but the exit 11 has an end processed at 90 °, and the bent portion is provided with a heater 12 to heat the laminated film passing therethrough. become. In this embodiment mode, heating is performed at 170 ° C. In addition, it is preferable to install the heating regulation plate 9 close to the heat roll. And the planar heating element 1 is obtained by cut | disconnecting the laminated | multilayer film bent continuously at a fixed space | interval.

  A plurality of the planar heating elements produced as described above were arranged and fixed with the sides of the bent portions in contact with each other. Then, electricity was applied in parallel, and the heat generation state was observed with an infrared thermograph. As a result, it was possible to suppress a decrease in temperature even at a connecting portion of a plurality of planar heating elements.

  As described above, the planar heating element according to the present invention can generate heat without gaps in the plane, and thus can be applied as a heater for floors and walls.

(A) Perspective view of planar heating element in Embodiments 1 and 2 of the present invention (b) Same sectional view (A) Sectional drawing of the planar heating element inserted and fixed in the heat insulating material in Embodiment 1 of this invention (b) The block diagram at the time of winding and fixing the planar heating element The perspective view of the jig | tool for a bending process in Embodiment 2 of invention Configuration diagram of conventional planar heating element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar heating element 2 1st resin film 3 PTC resistor 4 Electrode 5 2nd resin film 7 Heat insulating material 8 Part except a PTC resistor 9 Heating regulation board

Claims (7)

A first resin film having electrical insulation, a pair of electrodes and a PTC resistor formed by printing on the first resin film, and an electrical insulation covering the surfaces of the pair of electrodes and the PTC resistor A planar heating element comprising: a second resin film having at least a portion of the PTC resistor that is bent at 90 ° or more with respect to the PTC resistor. The planar heating element according to claim 1, wherein a part excluding the PTC resistor is embedded in a heat insulating material. The planar heating element according to claim 1, wherein a part excluding the PTC resistor is configured to be wound around a heat insulating material. The planar heating element according to claim 1, wherein the first resin film is a polyester resin film. The planar heating element according to claim 2 or 3, wherein the heat insulating material is made of polyurethane. A first resin film having electrical insulation, a pair of electrodes and a PTC resistor formed by printing on the first resin film, and an electrical insulation covering the surfaces of the pair of electrodes and the PTC resistor In the step of bending at least a part excluding the PTC resistor to 90 ° or more with respect to the PTC resistor, the first resin film and the second resin film A method of manufacturing a planar heating element obtained by using a heating regulation plate installed in a molding path of a laminated film. The manufacturing method of the planar heating element of Claim 6 which set the temperature of the heating regulation board to 190 degrees C or less.